Zeniff and his people cry mightily to the Lord and then go forth to battle against the Lamanites in the strength of the Lord. The Lord hears the cries of Zeniff and his people and answers their prayers.

Mosiah 9:17–18

17 Yea, in the strength of the Lord did we go forth to battle against the Lamanites; for I and my people did cry mightily to the Lord that he would deliver us out of the hands of our enemies, for we were awakened to a remembrance of the deliverance of our fathers.
18 And God did hear our cries and did answer our prayers; and we did go forth in his might; yea, we did go forth against the Lamanites, and in one day and a night we did slay three thousand and forty-three; we did slay them even until we had driven them out of our land.

Elder David A. Bednar said:

“Blessings require some effort on our part before we can obtain them, and prayer, as ‘a form of work, . . . is an appointed means for obtaining the highest of all blessings’ [Bible Dictionary, “Prayer”]. We press forward and persevere in the consecrated work of prayer, after we say ‘amen,’ by acting upon the things we have expressed to Heavenly Father.”

(“Ask in Faith,” Ensign or Liahona, May 2008, 95.)